Sewer cleanout outside house is 8 inches too tall

The cast iron sewer cleanout for my house is in a bad spot to be sticking up so high. It is about 10 feet outside my foundation wall and appears to be a 3" pipe sticking vertically out of the ground. But the pipe has a fitting that enlarges to a 4" at the end (just before where the cleanout plug is)

So I'd like to dig into the soil around the pipe, cut it off below the grade and put on a new plug - then put a "valve box" (the plastic jobbies usually seen around sprinkler valves?) over top of it.

I've never done any outdoor plumbing and I'm not sure if I'm overlooking something. Would I just put a rubber adapter (like a Fernco or Mission boot) over the cut end and then put on an ABS cleanout and plug?

I actually have installed and replaced a lot of DWV inside of houses, but I don't have even a beginner's understanding of where this sewer cleanout leads to and what I should be considering as far as future access. I've never seen a diagram of where the waste pipe goes after it enters the basement floor!

So you think the valve box isn't a good idea? I'm afraid of people not knowing where this cleanout is in the future...

you say "...glue on a female adapter"> I guess I should have been more clear: it is a 1920s house and the sewer cleanout is cast iron. That's why I was thinking a Fernco was necessary. What material of adapter should I use to be code? And is there any reason to attempt to make the pipe 4" at the plug (like it was before) or should I just use 3"?

Hi
I don't mean to press but it has been a week and I didn't hear back from HJ or another plumbing expert. Can someone read my original post and my follow-up and help me sort things out? I'm doing this tomorrow!

thanks

bingo said:

Hi HJ

So you think the valve box isn't a good idea? I'm afraid of people not knowing where this cleanout is in the future...

you say "...glue on a female adapter"> I guess I should have been more clear: it is a 1920s house and the sewer cleanout is cast iron. That's why I was thinking a Fernco was necessary. What material of adapter should I use to be code? And is there any reason to attempt to make the pipe 4" at the plug (like it was before) or should I just use 3"?

Your plan will work fine. Use a Fernco that will go from CI to either PVC or ABS, your choice. Stay with the 3", I see no reason to have a 4" hole immediately reduced to 3". A female adapter will allow you to use a screw-in plug. The irrigation box is a good idea. One alternate plan might be to figure how to hid the existing clean out with some shrubs and just leave it as is.

A female cleanout ferrule and a No-Hub coupling is all you need, once the pipe is cut off. I forgot, or missed, the cast iron part in my original answer because cast iron cleanouts are becoming very rare.